On the improvement of thermal comfort of university students by using electrically and chemically heated clothing in a cold classroom environment. (December 2015)

• Record Type: Journal Article
• Authors: Song, Wenfang; Wang, Faming; Zhang, Chengjiao; Lai, Dandan
• Is Part Of: Building and environment. Volume 94:Part 2(2015)
• Page Start: 704
• Page End: 713
• Publication Date: 2015-12
• Subjects: Thermal comfort -- Electrically heated clothing -- Chemically heated clothing -- University students -- Cold classroom environment; Buildings -- Environmental engineering -- Periodicals; Building -- Research -- Periodicals; Constructions -- Technique de l'environnement -- Périodiques; Electronic journals; 696
• DOI: 10.1016/j.buildenv.2015.10.017
• Languages: English
• ISSNs: 0360-1323

Abstract

Abstract: This study aimed to examine the effectiveness of two types of heated clothing (i.e., electrically and chemically heated clothing) in improving thermal comfort of university students while sitting in a simulated cold classroom environment. Eight male subjects performed three 90-min trials and three test scenarios were selected: EHC (i.e., electrically heated clothing), CHC (i.e., chemically heated clothing) and CON (i.e., the control, no heating). The trials were conducted in a climate chamber where the air temperature was 8.0 °C, RH = 80% and the air velocity was 0.17 m/s. Significantly higher mean skin (in both EHC and CHC) and body temperatures (in CHC) were found in the heated clothing compared to CON throughout the entire trials ( p < 0.05). The whole-, upper- and lower-body thermal (TS) and comfort sensations (CS) were improved in the heated clothing (rated 'Neutral' and 'Comfortable', respectively, throughout the test) than CON (aggravated with time) ( p < 0.05). Significantly higher finger temperatures (the 65–90th min, p < 0.05), finger blood flow (the 2–5th min in EHC and the 2–10th min in CHC, p < 0.05) and remarkably improved TSs at the hands and feet were detected in EHC and CHC than CON ( p < 0.05). Finger dexterity was improved in CHC at the end of the test than the beginning ( p < 0.05). CHC offered more heating benefits than EHC in terms of local skin temperature elevation at the trunk ( p < 0.05). In summary, the heated clothing could serve as an effective method to improve both local- and whole-body thermal comfort of university students while sitting in cold classrooms. Highlights: Two types of heated clothing (i.e., electrically heated clothing and chemically heated clothing) were designed. The performance of EHC and CHC in improving thermal comfort of university students in a cold environment was examined. Both EHC and CHC could effectively improve the local and whole body thermal comfort. Student performance, i.e., finger dexterity, was improved in CHC within the 90-min exposure.